Apparatus for measuing water impurities in oil

ABSTRACT

An apparatus for measuring water impurities in oil comprises a confined space in which the oil is heated to a temperature higher than the evaporation temperature of water. In accordance with the invention, the confined space is a chamber arranged between an inlet and an outlet and having heating means and temperature control means, said chamber being adapted, by way of valves provided in the inlet and the outlet, to form a closed system. The chamber has an expansion vessel connected thereto, which is of variable volume and has means for emptying it. Further, the closed system is provided with means for measuring and/or controlling the change of state produced by the heating of the oil.

United States Patent Lineberg [541 APPARATUS FOR MEASUING WATERIMPURITIES 1N OIL Inventor: Birger David Lineberg, Ekorrvaegen 7,Koping, Sweden Filed: April 14, 1970 App1.No.: 28,350

Int. Cl. ..Gln 11/00, GOln 33/28 Field of Search ..73/6l.l R, 61.3, 15 R[56] References Cited UNITED STATES PATENTS 3,511,083 5/1970 Reay et al...73/6l.l R 3,481,182 12/1969 Lineberg ..73/61.1 R 2,571,470 /1951Milligan ..73/61.1 R

Oct. 3, 1972 ABSTRACT An apparatus for measuring water impurities in oilcomprises a confined space in which the oil is heated to a temperaturehigher than the evaporation temperature of water. ln accordance with theinvention, the confined space is a chamber arranged between an inlet andan outlet and having heating means and temperature control means, saidchamber being adapted, by way-of valves provided in the inlet and theoutlet, to form a closed system. The chamber has an expansion vesselconnected thereto, which is of variable volume and has meansfor emptyingit. Further, the closed system is provided with means for measuringand/or controlling the change of state produced by the heating of theoil.

r w n Kie llllll llll PATENTEU 3 3 6 95 O 95 APPARATUS FOR MEASUINGWATER IMPURITIES IN OIL is also suited for the general determination ofwaterim-- purities lower than percent in oil or other liquid media whichare not appreciably vaporized at ternpgratures lower than 150 to 170 C.

Water impurities in oil for example when the oil is used for quenchingat hardening operations may produce explosive fires under unfavorableconditions in that the oil is wholly or partly heated to temperatureshigher than 100 C, when very heavy vaporization takes place. The samerisk exists when oil is used to transmit heat, as soon as the oil isheated to a temperature higher than 100 C. Critical water contents inthese uses are of the order of 0.1 percent. Quenching in oil athardening operations often takes place in an at mosphere containing int.al. H N and CO said gases being partly dissolved in the oil, which isnot either suitable.

Water impurities in oil are also dangerous when the oil is to be used inelectrical apparatus and for the lubrication of bearings and like means,for which reason it should be possible exactlyto determine the watercontent in all of these cases."An exact measuring of water impurities inoil is also necessary when the oil has been separated from e.g. wastewater or from ballast water in ships tanks and the oil is either to bedestroyed or purified. With oil separated from waste water supervisionof the water content shall take place 'over a broad range, usually 0.1to 5 percent. Also when the oil has been separated from ballast waterthe water content varies" considerably. In the cases where oil is usedasa coolant with admixture of water, for instance in cutting operations,it is important to have the possibility of measuring the water content,since the cooling properties of the coolant oil are deteriorated if thewater evaporates and the water content becomes too low. The respectivewater contents in this connection are in the order of 0.1 to 5 percent.

Whenever water impurities in oil involve the risk of accidents it isimperative to have a measuring apparatus which not only reliablymeasures the .water impurities but also is so designed that no measuringerrors can occur or in any case cannot occur without an alarm beinggiven that the apparatus is deficient in some way.

The above mentioned examples will show that there is a great demand fora reliable apparatus which permits measuring water impurities in oil,and to satisfy the requirements placed on such a measuring apparatus thepresent invention provides an apparatus of this kind which ischaracterized by the features that the confined space is a chamberarranged between an inlet and an outlet and having heating means andtemperature control .means, said chamber forming a closed system by wayof valves provided in the inlet and the outlet, that the chamber has anexpansion vessel connected thereto, which is of variable volume and hasmeans for emptying it, and that the closed system is provided with meansfor measuring and/or controlling the change of state produced by theheating of the oil.

The above and further features of the invention will become apparentfrom the following detailed description in which reference is made tothe accompanying figure diagrammatically illustrating a preferredembodiment of a measuring apparatus.

A heat insulated chamber in which the oil is to be heated is generallydesignated 1. The chamber has an inlet 2 and an outlet 3. The chambercontains heating means and. temperature control means which preferablyconsist of a temperature controlled heating cartridge 4. An expansionvessel generally designated 5 -is in communication with the chamber 1and is comprised as a unit in the confined space formed by the chamber1, the room 6 of the expansion vessel which is totake up oil, and abuffer space, if any, which shall prevent hot oil from reaching theexpansion vessel 5 and which may be in the form of a pipeline 7. Theexpansion vessel 5 is of such a design that the oil can be taken uptherein without getting in contact with ambient air, and therefore thevessel may suitably be a cylinder 9 having a piston 8. By reason of thedesign of the expansion vessel the oil in the room 6 will primarily beunder approximately atmospheric pressure. The piston 8 has a piston rodwhiclf serves as guide means and an indicator for the movements of thepiston, and besides the piston is operably means of compressed air or insome other manner for returning it to bottom position so that the room 6can be emptied by the piston providing a pumping action. A

To realize a measuring cycle dissolved gases, if any, must first beremoved from the oil as these may otherwise aifect the measuring resultso that wrong values for the water impurities are obtained.Degasification 5 takes place by pumping oil into the measuring chamber land the expansion vessel 5, the piston 8 reaching the top position b.l-l N and CO dissolved in the oil which gases show a lower solubility-athigher. temperatures than at lower temperatures as distinct from mostother gases escape because of the elevated temperature which arises bycold oil being mixed with hot oil and by the oil being heated by theheating cartridge 4. These gases collect in a dome 11 at the top of thechamber 1, and part of the gases is conducted from said dome 11 to theoutlet 3 when the piston 8 is pressed down to its intermediary positiona. The force pressing the piston down is then removed so that the pistonis capable of freely moving upwards until atmospheric pressure prevailsin the system. Dissolved gas possibly remaining in the oil then escapesand collects in the dome 11. The downwardly directed force is againapplied to the piston 8 which is pressed down into its bottom position0, all of said gas being pressed out of the measuring system. When saidlatter downward pressing of the piston has been concluded, thedownwardly directed force is again removed and atmospheric pressure canagain prevail in the confined space, whereupon valves 12 and 13 in theinlet 2 and outlet 3 are closed.

The conditions for an exact measuring have now been attained, that is, atemperature lower than the evaporation temperature of water, a pressureapproximately equal to atmospheric pressure, and oil free fromdisturbing insoluble gases, for which reason the measuring cycle propercan be initiated.

The measuring cycle is as follows: After the oil has thus beendegasified and the valves 12 and 13 closed,

the temperature of the oil is elevated to a value higher than theevaporation temperature of water at the pressure prevailing in theconfined system. This temperature is chosen with due regard. to thedesired measuring exactitude and to the desired working pressure, saidtemperature usually varying between from about 110 to 130 C. As the oilis degasified before the temperature rises above 95 C and the oil has arelatively small content of gasifiable constituents, which is always aprerequisite when the oil is to be used at elevated temperatures, it isonly the water occurring in the oil that can influence pressure orvolume changes according to the general law of the state of gases atfurther heating. Should, however, the pressure or volume change beconditioned by light components in the oil it is equally essential thattheir presence be indicated as the presence of water, because such gasescan occasion equally heavy damage as water.

At continued heating of the oil in the chamber 1 the volume of the oilincreases and fills out the expansion vessel 5 to an extent which isconstant since it is conditioned merely by the volume expansioncoefficient. By reason of the expansion vessel having been designed as acylinder 9 which a piston 8, said piston separates the measuring systemfrom any external influence other than the atmospheric pressure and thefrictional resistance of the piston, which becomes small and constantowing to' the lubricating and sealing properties of the oil. At thevolume increase the piston normally moves to the intermediary positiona. Should, however, water be present in the oil said water is evaporatedand the volume increase will be greater than normal, for which reasonthe piston 8 continues to move to its top position b where a stopabutment for the piston movement may be disposed. Should further waterbe present in the oil the pressure in the measuring system begins torise according to the general law of gases, and this pressure increaseis easily measured by means of a pressure gauge 14 the deflection ofwhich thus is a measure of the size of the water impurities in the oil.The volume of the cylinder and the permissible movements of the pistontherefore determines the measuring range; a longer piston stroke or alarger cylinder being chosen at larger water impurities. Thereforeseveral cylinders can be connected to the same measuring system viadifferent valves, and water contents from about 0.01 percent to morethan 1 percent can be measured with the desired exactitude.

After a finished measuring cycle the oil is pumped by the pump 15 undera pressure that by reason of the setting of the outlet valve 13 amountsto about twice the measuring pressure, the system being simultaneouslypressure tested since the system has to be absolutely tight in orderthat a reliable measuring result shall be obtained. Moreover, themovement of the piston for a normal volume expansion of the oilis sensedso that, if said piston movement is not attained, a signal is given toindicate that the apparatus is faulty. A wrong mea suring. result canalso be obtained if oil is not supplied because the supply line, afilter or the like is blocked, and the various operating phases aretherefore super vised by a time relay which delivers a signal, shouldthe various operating phases not have been carried out wit 'n normalintervals, course, the invention 15 not limited to the embodimentdescribed above with reference to the accompanying drawing, but permitsof modification within the scope of the appended claims. Thus themovable element of the expansion vessel 5 could be a diaphragm, bellows,enclosed air cushion or like means instead of a piston, and theactuating means of the movable element could be electrical orhydraulical instead of pneumatical. Besides, if desired, various filters16 or centrifuges 17 can be connected in the system, and as indicated at18 a control valve canbe connected between a point ahead of the inletvalve 12 and a point beyond the outlet valve 13. v

What I claim and desire to secure by Letters Patent 1. An apparatus forthe discontinuous measurement of water impurities in oil by heating theoil in a con fined space to a temperature higher than the evaporationtemperature of water comprising:

a container having a chamber with inlet and outlet means, said containerhaving heat and temperature control means; at least one expansion vesselconnected with said chamber, said expansion vessel being a cylinder andpiston unit with the piston of said unit being adapted to be actuated bythe volume increase of the oil which is responsive to the elevatedtemperature, and said cylinder having means for emptying the oil; saidchamber and said expansion vessel forming a closed system through saidinlet and outlet means, and said closed system having means forregulating and measuring the pressure produced by the heating of theoil, whereby the oil is degasified by reducing the volume in theexpansion vessel and the heating of the oil in said chamber so thatsaidmeasurement can be made.

2. The apparatus of claim 1 including a buffer means for the heated oilbetween said chamber and said expansion vessel.

3. The apparatus of claim 1 including a dome at the top of said chamberfor gases leaving said oil and said outlet means extending from saiddome.

4. The apparatus of claim 1 including expansion vessels of variousvolumes adapted for connection with said chamber.

1. An apparatus for the discontinuous measurement of water impurities inoil by heating the oil in a confined space to a temperature higher thanthe evaporation temperature of water comprising: a container having achamber with inlet and outlet means, said container having heat andtemperature control means; at least one expansion vessel connected withsaid chamber, said expansion vessel being a cylinder and piston unitwith the piston of said unit being adapted to be actuated by the volumeincrease of the oil which is responsive to the elevated temperature, andsaid cylinder having means for emptying the oil; said chamber and saidexpansion vessel forming a closed system through said inlet and outletmeans, and said closed system having means for regulating and measuringthe pressure produced by the heating of the oil, whereby the oil isdegasified by reducing the volume in the expansion vessel and theheating of the oil in said chamber so that said measurement can be made.2. The apparatus of claim 1 including a buffer means for the heated oilbetween said chamber and said expansion vessel.
 3. The apparatus ofclaim 1 including a dome at the top of said chamber for gases leavingsaid oil and said outlet means extending from said dome.
 4. Theapparatus of claim 1 including expansion vessels of various volumesadapted for connection with said chamber.